A fastening part such as a nylatch is used to fasten together a plurality of board-like members such as plates. A nylatch is a part to, for example, fasten two plates, is formed by a resin, etc., and is capable of locking and unlocking plates with/from each other at a touch. In fastening together plates using a nylatch, when the nylatch is forcibly inserted into holding holes formed in the plates, the tip of the nylatch is deformed and the nylatch is held by the plates.
Concerning a fastening structure using such a fastening part, Japanese Laid-Open Utility Model Publication No. 05-42722 discloses a trim with a clip wherein the clip is fitted to the trim in advance such that the clip is not detached from the trim, by fitting a spacer from the tip of the clip that is fixed penetrating the trim that is a board-like member and wherein the trim and a panel are fastened together by the clip by fitting the clip of the trim into a clipping hole of the panel (abstract, FIG. 3, etc.).
When the nylatch or the trim with a clip (Japanese Laid-Open Utility Model Publication No. 05-42722) is used as a fastening member, it is essential that the positions of the fitting holes for the nylatch or the clip to penetrate therethrough coincide among the members.
For the trim with a clip (Japanese Laid-Open Utility Model Publication No. 05-42722), the trim is fixed by sandwiching the trim using the head of the clip and the spacer and, thereby, the clip is adapted to avoid being pulled out from the trim. This clip is attached by forcibly inserting the clip into the hole in the panel and the holding hole of the clip is formed being larger than the shaft diameter.
When a nylatch is used, as depicted in FIG. 1, a nylatch 200 is fitted penetrating a holding hole 204 formed in a nylatch holding plate 202. An anchoring unit 206 of the nylatch 200 penetrates the holding hole 204 and, thereby, is caused to protrude on the backside of the nylatch holding plate 202. In this state, the anchoring unit 206 can be inserted into a fixing hole 210 of a plate to be fastened 208. That is, FIG. 1 depicts the nylatch 200 in its unlocked state.
To fasten together the nylatch holding plate 202 and the plate to be fastened 208, as depicted in FIG. 2, a locking bar-like portion 212 of the nylatch 200 is forcibly inserted in the direction indicated by an arrow “a” into the nylatch holding plate 202, which is directly put on the plate to be fastened 208, and the plate to be fastened 208, and the anchoring unit 206 is pushed to be opened in the direction of its diameter (arrow b) by the locking bar-like portion 212 inserted therein. As a result, the nylatch holding plate 202 and the plate to be fastened 208 are fastened together using the nylatch 200 as the medium and the nylatch 200 is locked.
As above, for the nylatch 200, the nylatch 200 is held in the holding hole 204 of the nylatch holding plate 202 and the anchoring unit 206 is inserted into the fixing hole 210 of the plate to be fastened 208. Therefore, it is essential that the position of the holding hole 204 and the position of the fixing hole 210 respectively of the nylatch holding plate 202 and the plate to be fastened 208 to be fastened together coincide or are close to each other. The precision of the hole diameter of each of the holding hole 204 and the fixing hole 210 is also important to maintain the precision of the fastening.
Because the nylatch 200 can be fitted at a touch as above, its workability is excellent. However, it is necessary to specify strict manufacture tolerances of the fitting plates that include the holding hole 204 and the fixing hole 210. As depicted in FIG. 3, assuming that a plurality of nylatches 200A, 200B and 200C are used, differences are generated between the positions of the holding holes 204 and those of the fixing holes 210 due to accumulation of the manufacture tolerances of the nylatch holding plate 202 and the plate to be fastened 208. Therefore, when the central axis O11 of the holding hole 204 and the central axis O12 of the fixing hole 210 are caused to coincide with each other to fix the nylatch 200A and the nylatch 200A is fixed, a position difference d11 (<d12) is generated between the central axis O11 of the holding hole 204 and the central axis O12 of the fixing hole 210 for the nylatch 200B that is adjacent to the nylatch 200A, and the position difference d12 (>d11) that is generated between the central axis O11 of the holding hole 204 and the central axis O12 of the fixing hole 210 for the nylatch 200C becomes larger. Therefore, though the nylatch 200B can be fixed, inconvenience occurs that the nylatch 200C even may not be inserted not to mention fixing of it, etc.
To enable a plurality of nylatches such as the nylatches 200A, 200B and 200C to be fixed, the differences caused by the manufacture tolerances need to be absorbed and the hole diameter of each of the holding holes 204 and the fixing holes 210 needs to be increased. When hole diameters φ11 and φ12 respectively of the holding hole 204 and the fixing hole 210 are set to be large, the insertion of the nylatch 200 becomes easy. However, as depicted in FIG. 4, when each of the hole diameters φ11 and φ12 is larger than an outer diameter φ10 of the nylatch 200, the fastening function of the nylatch 200 is degraded and, when the hole diameter φ11 of the holding hole 204 of the nylatch holding plate 202 is set to be φ11>φ10, the nylatch 200 may not be held in its unlocked state. In the case where the nylatch 200 is released from the nylatch holding plate 202, another nylatch needs to be prepared when the nylatch 200 is lost or when the nylatch 200 is tried to be again fitted, etc. Therefore, the workability is degraded.
Japanese Laid-Open Utility Model Publication No. 05-42722 includes no suggestion or no disclosure concerning the above problems and also includes no disclosure about any means of solving those problems.